Induction heating apparatus
US4359620A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 1979 |
| Grant date | Nov 16, 1982 |
| Priority date | — |
| Expiry date | Dec 17, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K3/0475
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An induction heating apparatus for heating an electrically conductive workpiece, comprising a C-shaped core made of a material having a high magnetic permeability and having two closely opposed tapered ends, an exciting coil surrounding the core, and a circuit for supplying a periodic voltage to the coil so as to cause a varying magnetic field to be produced in the core and to efficiently focus a field of high flux density between its two ends. In one embodiment the core is made of ferrite, a capacitance is connected with the exciting coil to form a resonant circuit, and circuitry is provided for detecting the phase of the current flowing in the resonant circuit and for controlling the frequency and phase of the periodic voltage supplied to the resonant circuit so as to maintain the circuit in resonance. In other embodiments, one of the two ends of the core is mounted on a slidable ram portion, which can be moved toward and away from the other end of the core, and electrically insulating workholders can be mounted on each end of the core to hold a workpiece in place as the ends of the core are pushed toward each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.